tolong d jawab yh buat bsk plis:) no 15,16,17,18,19,20

15) x + y - 2 = 0
y = - x - 2
m = - 1
gradien sejajar m1 = m2 = - 1
pers garis
y - y1 = m ( x - X1 )
y - 0 = - 1 ( x + 5 )
y = - x - 5
y + x + 5 = 0 ( C )

16) 2y - 3x = 6
2y = 3x + 6
m = 3/2
gradien saling tegak lurus
m1 . m2 = - 1
3/2 . m2 = - 1
m2 = - ⅔ ( B )

17) 4y - 2x = 8
4y = 2x + 8
m = 2/4
m = ½
gradien saling tegak lurus
m1 . m2 = - 1
½ • m2 = - 1
m2 = - 2
tegak lurus dg garis pers :
2x + y = 6
y = - 2x + 6
m = - 2 ( C )

18) y = 3x + 2
m = 3
gradien saling tegak lurus
m1 . m2 = - 1
3 . m2 = - 1
m2 = - ⅓
pers garis
y - y1 = m ( x - X1 )
y + 1 = - ⅓ ( x - 6 )
y = - ⅓x + 2 - 1
y = - ⅓x + 1 ( C )

19) pers garis 1
y - y1 = m ( x - X1 )
y - 3 = 3 ( x + 2 )
y = 3x + 6 + 3
y = 3x + 9
pers garis 2
( y - y1 ) / ( y2 - y1 ) = ( x - X1 ) / ( x2 - X1 )
( y + 7 ) / ( 11 + 7 ) = ( x + 5 ) / ( 4 + 5 )
( y + 7 ) / 18 = ( x + 5 ) / 9
9 ( y + 7 ) = 18 ( x + 5 )
9y + 63 = 18x + 90
9y = 18x - 63 + 90
9y = 18x + 27
y = 2x + 3
ttk potong
y1 = y2
3x + 9 = 2x + 3
3x - 2x = 3 - 9
x = - 6
subtitusi
y = 2x + 3
y = 2(-6) + 3
y = - 12 + 3
y = - 9
ttk potong ( - 6,-9 ) ( D )

20) garis y = - 3x
m = - 3
gradien saling sejajar
m1 = m2 = - 3
ttk potong
y1 = y2
2x + 7 = x + 2
2x - x = 2 - 7
x = - 5
subtitusi
y = x + 2
y = - 5 + 2
y = - 3
ttk potong ( - 5, - 3 )
pers garis
y - y1 = m ( x - X1 )
y + 3 = - 3 ( x + 5 )
y = - 3x - 15 - 3
y = - 3x - 18 ( tdk ada opsi pilihan )